Energy Secretary Steven Chu is taking responsibility for making the final decisions at two critical moments in the rise and fall of Solyndra.

First, Chu counseled with experts inside and outside the department, as well as senior aides, before deciding to grant the California solar company's application for a $535 million loan guarantee in March 2009, DOE spokesman Damien LaVera said in an email to POLITICO.

Almost two years later, in February 2011, Chu green-lighted new terms for Solyndra's loan in a way that allowed private investors, rather than taxpayers, to be the first to get paid back in the event of a default. That decision came despite warnings that the company was on the brink of going belly-up.

Chu's role at those two key moments of the Solyndra saga has been a missing puzzle piece for House Republicans in their investigation into the solar company's collapse, even as some of his subordinates have taken the heat.

Earlier this month, GOP members of the Energy and Commerce Committee’s oversight subpanel peppered DOE loan office chief Jonathan Silver with questions over who was responsible for approving the Solyndra loan and its restructuring amid numerous caution flags — if not outright red lights — from market analysts and officials across the government.

Silver replied that he wasn't at DOE in the early days of the Obama administration when the loan went out, and he didn’t have any knowledge of Chu's role in the process. The comment only angered the Republicans more.

"So no one is responsible?" asked Rep. Tim Murphy (R-Pa.). "This is an incredible organization you work for, that no one in the federal government is responsible for a half a billion dollars in taxpayer money. This is phenomenal. What do you do for a living?"

Chu will eventually get his chance to explain his role in the sequence of events when he appears — perhaps as early as October — at a House hearing on Solyndra. He can expect a politically charged atmosphere. Republicans, after all, have already called for Silver to be fired and haven't ruled out making the same case for Chu's dismissal.

What the lawmakers will likely hear from the Nobel Prize-winning physicist is an explanation that he’s always been the key decider in the Solyndra process, with a record articulated in dozens of public statements and interviews given over the last 2½ years.

Chu’s message has been clear: Hearing calls from top GOP and Democratic lawmakers, including during his Senate confirmation hearing, he wanted to break through red tape inside DOE and at rival Cabinet agencies that had resisted getting loan guarantees out the door for several years after their authorization by the Energy Policy Act of 2005.

At a March 2009 event hosted by The Washington Post, where Chu announced Solyndra's selection, he recounted one of his initial briefings with a DOE career staff who told him that the first guarantees would not be ready until mid-2010.

"We've accelerated and streamlined the process and the loans are coming out and this is the first one," Chu said, referring to Solyndra. "We're trying to streamline it so that the period of time will be reduced from a scale of four years to several months."

During a February 2009 interview with The Wall Street Journal, Chu said one of his biggest hurdles in the loan guarantee program was dealing with a "very conservative legal department" at DOE that wants to wait for all applications to come in before they start vetting.

"I'm not convinced that the level of documentation that's been asked for is required," Chu said. "It might be too much."

Chu, who came to DOE from academia and a post as director of the Lawrence Berkeley National Laboratory, never hid his desire to shake things up with his new job.

In the Journal interview, he said he would be spending a third of his time getting the loan guarantee program going, even though he had just a skeletal staff of advisers. To supplement his team, he said he’d lean on Agriculture Secretary Tom Vilsack, who had experience in moving federal dollars out the door, and would send his own people into the inner sanctum of DOE to speed things up.

"It means you have to go into gory detail: ‘What is it you’re requiring, why do you think you need this?'" Chu said. "I have my advisers actually going down rolling up their sleeves and asking, 'OK, what is it that you're requiring? Is this really necessary?'"

By March 2010, Chu said he was still dealing with hurdles, telling the Journal in another interview that it was difficult to persuade the Office of Management and Budget to accept DOE’s cost estimates for loan guarantees and loan insurance. He also said he was trying to navigate the critical question of how to decide who gets repaid first if a loan recipient defaults.

"There is always government bureaucracy. We are trying our best to cut that down to the bone, but there are statutes," Chu said. "For example, the loans. Why does it take so long to get a loan out? Well, we are required by statute to do certain things. We have to protect the taxpayer interests. We have to make sure when we give a loan that there's a reasonable probability of getting it back."

Republicans investigating the Solyndra mess have homed in on the repayment issue — known as subordination — arguing that someone in the Obama administration changed the terms of the 2005 Energy Policy Act by allowing Solyndra's private investors to cut to the front of the line ahead of the taxpayers.

Rep. Cliff Stearns (R-Fla.), the chairman of the oversight subcommittee, said last week that he still didn’t know if Chu was responsible for changing the terms of the loan.

When the energy secretary comes in for questioning, Stearns said he plans to ask about internal documents uncovered via subpoena showing that staff at DOE and OMB didn't think Solyndra's business plan could keep it afloat.

Based on conversations with several department lawyers, a former Bush DOE official said Chu made decisions on Solyndra’s loan that disregarded their advice.

"He stacked the deck and either went around the general counsel's office or stacked the deck before things got to the general counsel's office," the former Bush DOE official said. "It's one thing to try to speed things up and make them more efficient. It's another thing to say let's expedite this at the cost of the substance of the law or regulation."

LaVera, the DOE spokesman, said Chu was looking out for taxpayers’ interests when he approved the new terms of Solyndra’s loan.

"The secretary gave final approval for the deal because, based on the information we had available to us at the time, we concluded that this restructuring gave Solyndra and its workers the best possible chance to succeed in a very competitive marketplace and put the company in a better position to repay the loan,” LaVera said.

While Chu may have his answers down on the Solyndra loan and the overall program, he can still expect several uncomfortable questions about his interactions on the issues with other high-ranking Cabinet officials.

According to the Los Angeles Times, Chu disagreed with Treasury Secretary Timothy Geithner and then-National Economic Council Director Lawrence Summers during a Cabinet meeting last fall over just how strict the review process should be for federal loan guarantees like those that Solyndra received. Chu had wanted less scrutiny from OMB and the Treasury Department, the newspaper reported.

Republicans earlier this month also released a Jan. 31 email obtained by subpoena that showed OMB officials discussing the political implications for President Barack Obama’s 2012 reelection if Solyndra defaulted on its loan.

Noting a meeting scheduled for Feb. 1 between OMB Director Jack Lew and Chu, one official suggested that Lew "flag to DOE at the highest level the stakes involved, for the secretary to do as he sees fit (and be fully informed and accountable for the decision)."

"If Solyndra defaults down the road, the optics will arguably be worse later than they would be today," wrote one OMB official, whose name was redacted from the email. "In addition, the timing will likely coincide with the 2012 campaign season heating up."

Chu and Lew did meet on Feb. 1 "to discuss a variety of topics," LaVera said.

"While I cannot confirm which topics were specifically addressed, this email is yet another piece of evidence that political or optical considerations took a back seat to putting the company and its workers in a better position to succeed and repay the loan," he added.

With so much buzz around Chu’s involvement in Solyndra, Jason Grumet, president of the Bipartisan Policy Center, said the Energy secretary’s challenge during tough House hearings will be to talk up the broader benefits of the loan guarantee program.

"People are very upset about the situation. One thing Secretary Chu can do very well is just remind people of the innovation process without necessarily defending this particular situation," Grumet said.

Salo Zelermyer, a former Bush DOE attorney now working at Bracewell & Giuliani, said the jury is still out on how Chu will fare during the lengthy investigation that awaits him, especially with GOP lawmakers eager to draw blood.

"He seemed determined to make changes to the program to, in his mind, make it more nimble and efficient," Zelermyer said. "I'm sure he didn't intend for those measures to result in an increased chance of a failed loan guarantee, but that's for everybody else's judgment to make."

This article first appeared on POLITICO Pro at 8:38 a.m. on September 29, 2011.